Powder compacting apparatus

ABSTRACT

A powder compacting apparatus comprising a punch and die assembly including a die plate with at least one die cavity therein and at least one lower punch for reciprocal movement into the die cavity to compact powdered material therein. A work station positioner transversely movable across the upper surface of the die plate has an upper punch adapted to be aligned with the die cavity and moved in timed relationship with the lower punch such that the powdered material is compressed between the two punches to form a compacted article.

United States Patent [191 Smith et a1.

[ Nov. 27, 1973 POWDER COMPACTING APPARATUS [73] Assignee: Wolverine-Pentronix Inc., Lincoln Park, Mich.

221 Filed: July 27,1971

21 Appl. No.: 166,507

[52] U.S. C1 425/78, 425/344, 425/352, 425/415 [51] Int. Cl B30b 11/02 [58] Field of Search 425/78, 344, 352, 425/415, 354, 337, 336, 411, 412, 41 7, 77

[56] References Cited UNITED STATES PATENTS 3,020,589 2/1962 Maritano 425/78 2,135,803 11/1938 Dumert 4?.5/415 X 3,156,011 11/1964 Olson 425/78 X 2,540,457 2/1951 Rice 425/78 X 2,570,989 10/1951 Seelig 425/78 3,191,231 6/1965 Went0rf.... 425/77 2,360,528 10/1944 Tolmage 425/78 X 3,545,045 12/1970 Vinson 425/344 X 3,574,892 4/1971 Smith 425/193 X Primary Examiner-J. Howard Flint, Jr. Att0rney-Robert C. Hauke et a1.

[5 7] ABSTRACT A powder compacting apparatus comprising a punch and die assembly including a die plate with at least one die cavity therein and at least one lower punch for reciprocal movement into the die cavity to compact powdered material therein. A work station positioner transversely movable across the upper surface of the die plate has an upper punch adapted to be aligned with the die cavity and moved in timed relationship with the lower punch such that the powdered material is compressed between the two punches to form a compacted article.

9 Claims, 3 Drawing Figures United States Patent 1 [1 1 3,775,032 Smith et al. [451 Nov. 27, 1973 POWDER COMPACTING APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to powder compacting apparatus and, more particularly, to an improved punch and die assembly for such apparatus having means providing an improved operation for the compaction of a powdered material.

2. Description of the Prior Art The present invention is an improvement over the punch and die assemblies and work station positioners of the character disclosed as part of a powder compacting press disclosed in U. S. Pat. No. 3,574,892 issued Apr.'13, 1971 for Powder Compacting Press, which is assigned to the assignee of the present application. The apparatus disclosed in the aforementioned patent consist of a machine for the purpose of manufacturing compacted articles such as toroids, beads, pellets and the like made of powdered ferrite, glass or other comparable powder substances capable of forming a compacted article upon the application of a pressure in a confined die cavity.

In the powder compacting press disclosed in the aforementioned U. S. Patent, the articles are compacted and formed in a multi-cavity die forming part of a punch and die set, with the finished articles being automatically ejected from the die cavities, picked up by a pick-up head, and dropped through discharge ports into suitable receptacles. The work station positioner assembly, which is part of the press, is mounted angularly movable transversely over the die plate and carries a powder dispenser, an anvil and the pick-up head. The powder dispenser, which is supplied with powder from a primary powder supply means connected thereto by means of a flexible tubing or the like, is first positioned over the die cavity or cavities which are thus filled with powder as the punches are displaced downwardly so as to draw a predetermined amount of powder into the die cavity or cavities..The dispenser is then removed from above the die cavity or cavities by the subsequent angular motion of the station positioner assembly, and the anvil is, in turn, positioned over the die cavities. The anvil is clamped over the die cavity by means of a pivotable clamp supported above the anvil and actuated in timed relation with the movement of the punches. The anvil is held down with sufficient pressure to permit the compaction of the powder against the anvil as a result of an upward motion of the punches into the die cavity or cavities. The anvil is then removed from its position over the die cavity or cavities and is replaced as a result of the pick-up head by a further angular motion of the work station positioner transversely across the face of the die plate. The punches are displaced upwardly so as to bring their upper ends in substantial flush alignment with the upper surface of the die plate, such that the finished compacted articles are ejected from the die cavities and picked up by the pick-up head. As the result of a return angular motion of the work station positioner to the initial fill position, the pick-up head is removed from over the die cavity and is disposed over one or, if a plurality of die cavities are employed, a series of discharge apertures arranged in a disposition similar to the arrangement of the die cavities in the die plate,'and the finished compacted article or articles are dropped through the discharge aperture or apertures into a container or separate containers.

The punch and die assembly described in the aforementioned US. Patent is particularly useful for forming articles having a torroidal or tablet-like shape, but cannot be readily modified to form compacted articles having a nonuniform surface configuration on the side associated with the anvil.

SUMMARY OF THE INVENTION In accordance with the present invention, an improved powder compacting press is provided having an anvil carrying a reciprocally mounted upper punch adapted to be positioned over a die cavity and displaced in timed relationship with a lower punch into the die cavity to compact a powdered material therein into an article having at least a non-uniform surface configuration on the side associated with the anvil.

The objects, advantages and applications of the present invention will become apparent to those skilled in the art of powder compacting presses when the accompanying description of an example of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and in which:

FIG. 1 is a cross-sectional view through the die plate and punch assembly of a powder compacting press, constructed in accordance with the principles of the present invention and illustrating an anvil disposed over a die cavity with the punches in position at the start of a compaction stroke;

FIG. 2 is a fragmentary cross-sectional view similar to FIG. 1 illustrating the position of the upper and lower punches after the powdered material has been compacted into a finish article; and

FIG. 3 is a fragmentary cross-sectional view taken along line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and, in particular to FIG. 1, there is shown an example of the present invention in the form of a die and punch assembly 10, having a die plate 12 adapted to be seated in a table, not shown, which forms a portion of a powder compacting press similar to the type disclosed in the aforementioned U. S. Pat. No. 3,574,892. The die plate 12, preferably, has a flat upper surface 14 that is held to the press table by any suitable means such as clamps, screws or the like, not shown. The die plate 12 is provided with a symmetrically shaped aperture 18 formed about an axis 20, which is disposed normally to the upper surface 14 of the die plate 12. A cylindrically shaped die bushing 22, preferably formed of a hard material such as a carbide, is retained within the aperture 18 by a suitable adhesive material disposed between the outer periphery of the die bushing 22 and the surface of the aperture 18. A suitable adhesive, which may be used between the outer periphery of the die bushing 22 and the surface of the aperture 18, may be a commercial quick-setting bonding compound such as an anaerobic adhesive which will securely maintain the die bushing 22 within the aperture 18 when subjected to pressure during the compacting operation, which will be described hereinafter. An example of a bonding compound which may be used is known and marketed under the name of LOCTITE, manufactured by the Loctite Corporation, Newington, Conn. The compound, which is particularly useful in the bonding of cylindrical parts, has a high sheer strength, exceeding that of conventional press-fitted parts by up to five times. The compound Loctite has excellent heat and solvent characteristics, as well as providing a high sheer strength between adjoining interfaces.

As can best be seen in FIG. 1, the die bushing 22 is disposed in the aperture 18 such that the upper surface 19 of the die bushing 22 is flush with the upper surface 14 of the die plate 12. The die bushing 22 has a centrally disposed bore 24, which for purpose of illustration is shown as being rectangular in cross-section, although it is obvious that the bore 24 may be circular, square, oval or of any appropriate shape in crosssection according to the desired peripheral shape of the article to be compacted therein. The bore 24 extends normally downward from the upper surface 19 of the die bushing 22 and may be provided with a charnfered portion (not shown) at the lower end thereof. Although only one bore 24 is shown, it is to be understood that the die bushing 22 may be provided with a plurality of mutually parallel bores, for example in a circular arrangement around the axis 20 of the die bushing and having a regular peripheral spacing with each of the parallel bores extending normally downwardly from the upper surface 19 of the die bushing 22.

The die plate 12 is further provided with a pair of diametrically opposed longitudinal bores 28 and 29 (shown only in FIG. 3) radially spaced from the axis 20 by predetermined equal distances. Respectively associated with each bore 28 and 29, there is one of a pair of downwardly extending support posts 32 and 34. The support posts 32 and 34 are of an elongated cylindrical shape and are retained within their respective bores 28 and 29 by any suitable adhesive, such as the Loctite adhesive, or otherwise fastened into the bores 28 and 29 such as by a press-fitted assembly or by means of set screws.

The die and punch assembly further comprises a core rod support plate 36 (FIG. 1) of a generally cylindrical shape and which is provided with a central aperture 38 in which a core rod insert 40 is bonded by a suitable adhesive, all of which will be described in detail hereinafter. The core rod support 36 is also provided with a pair of diametrically opposed longitudinal bores 42 (FIG. 3) which are radially spaced from the axis by the same distance as the bores 28 and 29 in the die plate 12. The core rod support plate 36 is positioned at a selected distance from the lower surface of the die bushing 22 by means of a sliding engagement between the bores 42 and the support posts 32 and 34. A pair of threaded passages 44 radially extend from the outer periphery of the core rod support plate 36 and terminate at the bores 42, with the threaded passages 44 accommodating set screws 46. The core rod support plate 36 may be adjusted on the support posts 32 and 34 at a selected distance from the lower surface of the die bushing 22 and is locked in place by means of the set screws 46.

The die and punch assembly 10 further comprises a punch upper support member 48, which is provided with a centrally disposed bore 50 supporting a punch insert member 52 having an outer periphery complementary to the bore 50 and including a shoulder 54 in abutment with the upper surface of the support member 48. The insert member 52 has a centrally disposed bore 60 in which the lower end of a lower compacting member or punch 62 is received. The punch 62 extends upwardly from the upper support member 48 and is narrowed down to a rectangularly shaped shank 63 that is complementary to the shape of the die plate bore 24. The punch insert member bore 60 and the punch 62 have a suitable adhesive, such as the aforementioned Loctite, applied between their engaged surfaces so as to secure the punch 62 within the insert member bore 60. The punch insert member 52 is, in turn, bonded to the punch upper support 48 by the adhesive Loctite.

As can best be seen in FIG. 3, the punch upper support 48 is also provided with a pair of diametrically opposed longitudinal bores 64, which are radially spaced from the axis 20 by the same distances as the die plate bores 28 and 29. A sliding engagement between the upper support 48 and the posts 32 and 34 permits a proper alignment of the upper end 66 of the punch 62 with the die bore 24, such that the punch 62 extends axially upwardly from the support 48 to register with the die bushing bore 24.

The punch 62 has an outer rectangular peripheral shape contoured to accurately and slidably fit the inner diameter and contour of the die bore 24, such that the punch 62 when engaged within the die bushing bore 24 defined a die cavity 67 (FIG. 1). The punch 62 also has a pair of longitudinal bores 68 each closely fitting the outer diameter of each of a pair of core rods 70 which are disposed within the punch longitudinal bores 68 for relative sliding movement, such that the punch 62 is slidably guided over the core rods 70 and the punch 62 is free for longitudnal movement relative to the core rods 70. The core rods 70 extend downwardly through appropriate bores within the upper support 48 and into retaining bores 76 in core rod inserts 40, wherein the core rods 70 are held by any suitable means, such as the aforementioned adhesive Loctite.

The punch upper support 48 functions to transmit an upwardly directed force from an actuating ram 72 (FIG. 1) to a powder material within the die cavity 67. This is accomplished as a result of the punch upper support 48 being coupled to the actuating ram 72 by a punch lower support 78 (FIG. 1), which in turn has a pair of diametrically opposed longitudinal bores, not shown, (similar to the bore 64 in the upper support 48) which slidably engage the posts 32 and 34 to guide the punch lower support 78 during reciprocal movement thereof under the actuation of the actuating ram 72 to maintain the punch lower support 78 in proper alignment with the punch upper support 48. The punch lower support 78 is connected to the punch upper support 48 by a pair of threaded members 82 which are shown in FIGS. 1 and 2. Each threaded member 82 extends axially upwardly through a bore 84 in the punch lower support 78 and threadedly engages a threaded bore 86 in the punch upper support 48. A sleeve member 88 surrounds each threaded member 82 with the upper and lower end faces of each sleeve member 88 being respectively in abutment with the lower and upper surfaces of the punch supports 48 and 78. Thus, as the end of each threaded member 82 is threaded into the threaded bore 86 in the punch upper support 48,

the punch upper support 48 and lower support 78 are fixedly secured to one another and reciprocate as a unit under the motion of the actuating ram 72. A pair of diametrically disposed bores 90, disposed in the core rod support 36, slidably receive the outer periphery of each sleeve member 88. The pair of threaded members 82 are symmetrically disposed relatively to the axis 20 and angularly disposed from the support posts 32 and 34 by 90".

An anvil block 126 is mounted in an aperture 127 in an oscillating arm 94 of a station positioner assembly 92 by any convenient means such as set screws or the like, not shown. The anvil block 126 has a centrally disposed longitudinal guide bore 144, having a contour complementary to the die bushing bore 24 and adapted to be aligned therewith by means of the oscillating arm 94 of the station positioner assembly 92. The guide bore 144 slidably supports an upper or anvil punch 146 which, in turn, is fixedly attached within a recess 147 (FIG. 3) in the lower surface of an anvil punch support 148 by any suitable means, such as the aforementioned adhesive Loctite. Belleville springs 150 disposed between an enlarged diameter portion 152 of the anvil punch support 148 and the upper surface 154 of the anvil block 126 normally biases the anvil punch support 148 and thus the anvil punch 146 upwardly away from the die plate 12 to the position shown in FIG. 1, such that the powder compacting face 156 of the anvil punch 146 does not engage the die plate surface 19 when the anvil .is moved transversely across the die plate 12 as hereinafter described. Downward movement of the anvil punch support 148, and thus the downward movement of the anvil punch into the die cavity 67, is limited by the abutment of an annular shoulder 157 formed on the punch support 148 with the upper surface 154 of the anvil block 126.

A typical powder compacting cycle includes a pow der filling step, a powder compacting step, and a completed article ejection step. Briefly, during the powder filling step, which is not illustrated, a powder supply device, which is commonly referredto as a powder hopper, and which is supported by the oscillating arm 94 of the stationer assembly 92 is disposed over the'die plate 12, completely encompassing the die bushing 22 so as to fill with a powder material the die cavity 67 defined by the bore 24 at the upper end 66 of the punch 62. After the filling operation, the hopper is removed from over the die cavity and replaced by the anvil block 126. The station positioner assembly 92, supporting the powder hopper and the anvil block 126, is mounted on the top of the compacting press table for an angular sweeping movement around a vertical axis transversely across the die cavity 67 in a timed sequence as caused by a drive mechanism which, in turn, actuates the actuating ram 72. A detailed explanation of the operation and construction of the station positioner assembly and the drive mechanism therefor may be had by reference to the aforementioned U. S. Pat. No. 3,574,892.

When the anvil block 126 is positioned over the die plate 12 and the guide bore 144 is in alignment with the die bushing bore 24, the upper surface of the anvil punch support 148 is in alignment with a pivotal clamp 158 which is adapted to be supported on a shaft actuated by a lever upon movement of the press drive mechanism at the same time as the actuating ram 72 is displaced upwardly to drive the lower punch 66 into the die cavity 67 during the compacting step. A detailed description of the pivotal clamp 158 may be had by reference to the aforementioned U. S. Pat. No. 3,574,892. As the pivotal clamp 158 is lowered under the action of the press drive mechanism, the end of the pivotal clamp 158 engages the upper surface of the anvil punch support 148 to drive the same downwardly and thus drive the anvil punch 146 into the die cavity 67 at the same time as the actuating rain 72 is displacing the lower punch 66 upwardly into the die cavity 67, such that both the anvil punch 148 and the lower punch 66 compact the powdered material contained within the die cavity 67 to a finished compacted article 160 (FIGS. 2 and 3), while simultaneously compressing the Belleville springs 150 between the anvil block 126 and the anvil punch support 148.

The upper portion of each core rod 70 has a beveled section 162 which functions to provide a chamfer at the end of the core hole formed in the finished article 160. The upper ends of each core rod 70 is of a reduced dimeter which is adapted to be received in aligned parallel bores 164 in the anvil punch 146 when the same is at the end of its compaction stroke as shown in FIGS. 2 and 3.

After the compaction of the article 160, the pivotal clamp 158 is raised under the action of the press drive mechanism, thereby relieving the pressure on the anvil support 148, whereupon the compressed Belleville springs 150 expand to raise the anvil punch 146 out of the die cavity 67, while simultaneously the lower punch 62 is displaced slightly downwardly so as to relieve the pressure applied by the punch end 66 on the bottom surface of the compacted article 160.

The oscillating positioner arm 94 of the station positioner assembly 92 is then pivoted about its vertical axis so as to transversely move the anvil block 126 from over the die cavity 67 and to replace the same by a suitable pick-up, such as a vacuum pick-up head (not shown), whereupon the finished article is ejected from the die cavity 67 as a result of the upward movement of the lower punch 52. The pick-up head then may be transversely moved by the oscillating positioner arm 92 so as to be disposed over appropriate apertures in the die plate 12 for depositing therethrough the finished articles for conveyance to a suitable container.

It is to be understood that the example of the present invention as disclosed herein constitutes one preferred form and that other forms might be adopted, all within the spirit of the invention and the scope of the appended claims.

What is claimed is as follows: 1. An apparatus for making an article of compacted powder material comprising a die plate having at least one die cavity of a predetermined cross-sectional configuration adapted to be filled with a powder material; an anvil having a lower surface constantly in engagement with said die plate and transversely movable from a position away from said die cavity to a position above said die cavity; said anvil having a guide bore therein and being coaxially aligned with said die cavity when said anvil is displaced over said die cavity; an upper compacting member having a portion with the same cross-sectional configuration as said die cavity, said upper compacting member being continuously disposed within said anvil guide bore and slidably reciprocable for movement into said die cavity when said anvil is positioned over said die cavity;

means carried by said anvil for normally biasing said upper compacting member away from said die plate during transverse movement of said anvil;

a lower compacting member having a portion with the same cross-sectional configuration as said die cavity engaged in said die cavity, said lower compacting member being operable for movement in said die cavity toward said upper compacting memher as said upper compacting member moves into said die cavity, such that said upper and lower compacting members exert a compacting pressure on said powder material to compact said powder material within said die cavity to form said article; and

means carried by said apparatus to engage said upper compacting member only when the anvil guide bore is aligned with the die cavity so as to move said upper compacting member into said die cavity.

2. The apparatus defined in claim 1 further comprising means carried by said anvil for limiting the movement of said upper compacting member into said die cavity.

3. The apparatus defined in claim 1 wherein the means carried by said anvil for normally biasing said upper compacting member away from said die cavity comprises a spring having one end bearing against a portion of the anvil and another end bearing against a portion of said upper compacting member so as to bias said upper compacting member away from said die plate.

4. The apparatus defined in claim 1 wherein the powder compacting face of said upper compacting member has a non-uniform contour.

5. The apparatus defined in claim 1 wherein said anvil has a shoulder formed thereon in a radial disposition with respect to said anvil guide bore, and said upper compacting punch has a radially enlarged portion adapted to engage said shoulder to limit the downward movement of said upper compacting member into said die cavity.

6. The apparatus defined in claim 5 wherein said hiasing means comprises a spring surrounding said upper compacting member, having one end bearing against said anvil and another end bearing against an enlarged radial portion of said upper compacting member so as to bias said upper compacting member away from said die plate.

7. The apparatus defined in claim 6 wherein said spring is a disc type spring.

8. The apparatus defined in claim 1 wherein said upper compacting member comprises upper and lower members releasably secured to one another, the lower face of said lower member having a defined contour adapted to compact said powdered material when the upper member of said upper compacting member is engaged by said last mentioned means.

9. The apparatus defined in claim 8 wherein said upper and lower portions of said upper compacting members are attached by means of an adhesive. 

1. An apparatus for making an article of compacted powder material comprising a die plate having at least one die cavity of a predetermined cross-sectional configuration adapted to be filled with a powder material; an anvil having a lower surface constantly in engagement with said die plate and transversely movable from a position away from said die cavity to a position above said die cavity; said anvil having a guide bore therein and being coaxially aligned with said die cavity when said anvil is displaced over said die cavity; an upper compacting member having a portion with the same crosssectional configuration as said die cavity, said upper compacting member being continuously disposed within said anvil guide bore and slidably reciprocable for movement into said die cavity when said anvil is positioned over said die cavity; means carried by said anvil for normally biasing said upper compacting member away from said die plate during transverse movement of said anvil; a lower compacting member having a portion with the same crosssectional configuration as said die cavity engaged in said die cavity, said lower compacting member being operable for movement in said die cavity toward said upper compacting member as said upper compacting member moves into said die cavity, such that said upper and lower compacting members exert a compacting pressure on said powder material to compact said powder material within said die cavity to form said article; and means carried by said apparatus to engage said upper compacting member only when the anvil guide bore is aligned with the die cavity so as to move said upper compacting member into said die cavity.
 2. The apparatus defined in claim 1 further comprising means carried by said anvil for limiting the movement of said upper compacting member into said die cavity.
 3. The apparatus defined in claim 1 wherein the means carried by said anvil for normally biasing said upper compacting member away from said die cavity comprises a spring having one end bearing against a portion of the anvil and another end bearing against a portion of said upper compacting member so as to bias said upper compacting member away from said die plate.
 4. The apparatus defined in claim 1 wherein the powder compacting face of said upper compacting member has a non-uniform contour.
 5. The apparatus defined in claim 1 wherein said anvil has a shoulder formed thereon in a radial disposition with respect to said anvil guide bore, and said upper compacting punch has a radially enlarged portion adapted to engage said shoulder to limit the downward movement of said upper compacting member into said die cavity.
 6. The apparatus defined in claim 5 wherein said biasing means comprises a spring surrounding said upper compacting member, having one end bearing against said anvil and another end bearing against an enlarged radial portion of said upper compacting member so as to bias said upper compacting member away from said die plate.
 7. THe apparatus defined in claim 6 wherein said spring is a disc type spring.
 8. The apparatus defined in claim 1 wherein said upper compacting member comprises upper and lower members releasably secured to one another, the lower face of said lower member having a defined contour adapted to compact said powdered material when the upper member of said upper compacting member is engaged by said last mentioned means.
 9. The apparatus defined in claim 8 wherein said upper and lower portions of said upper compacting members are attached by means of an adhesive. 